a. Technical Field
This disclosure generally relates to a medical device for diagnosis or treatment of tissue in a body and method for fabricating the same. In particular, the instant disclosure relates to the joining of various members and/or components in shafts of a medical device.
b. Background Art
This background description is set forth below for the purpose of providing context only. Therefore, any aspects of this background description, to the extent that it does not otherwise qualify as prior art, is neither expressly nor impliedly admitted as prior art against the instant disclosure.
Electrophysiology catheters are used in a variety of diagnostic, therapeutic, and/or mapping and ablative procedures to diagnose and/or correct conditions such as atrial arrhythmias, including for example, ectopic atrial tachycardia, atrial fibrillation, and atrial flutter. Arrhythmias can create a variety of conditions including irregular heart rates, loss of synchronous atrioventricular contractions, and stasis of blood flow in a chamber of a heart, which can lead to a variety of symptomatic and asymptomatic ailments and even death.
A catheter may be deployed and manipulated through a patient's vasculature to the intended site, for example, a site within a patient's heart or a chamber or vein thereof. The catheter may carry one or more electrodes that can be used for cardiac mapping or diagnosis, ablation and/or other therapy delivery modes, or both, for example. Once at the intended site, treatment can include, for example, radio frequency (RF) ablation, cryoablation, laser ablation, chemical ablation, high-intensity focused ultrasound-based ablation, microwave ablation, and/or other ablation treatments. The catheter may impart ablative energy to cardiac tissue to create one or more lesions in the cardiac tissue and oftentimes a contiguous or linear and transmural lesion. This lesion disrupts undesirable cardiac activation pathways and thereby limits, corrals, or prevents errant conduction signals that can form the basis for arrhythmias.
To position a catheter within the body at a desired site, some type of navigation may be used, such as using mechanical steering features incorporated into the catheter (or an introducer sheath). In some examples, medical personnel may manually manipulate and/or operate the catheter using the mechanical steering features.
In order to facilitate the advancement of catheters through a patient's vasculature, the simultaneous application of torque at the proximal end of the catheter and the ability to selectively deflect the distal tip of the catheter in a desired direction can permit medical personnel to adjust the direction of advancement of the distal end of the catheter and to position the distal portion of the catheter during an electrophysiological procedure. The proximal end of the catheter can be manipulated to guide the catheter through a patient's vasculature. The distal tip can be deflected by a pull wire attached at the distal end of the catheter that extends to a control handle that controls the application of tension on the pull wire.
Two of the mechanical considerations for a catheter shaft are that it transmit torque and resist compression during use. Substantial frictional forces sometimes resist transmission of torque across the length of the catheter. In some cases, these forces can cause the catheter shaft to twist about a longitudinal axis of the catheter shaft, storing energy in the process in a spring-like fashion. If the energy is released suddenly, the distal end of the catheter, which may be deflected by a steering mechanism, can be undesirably propelled with significant force.
With respect to resisting compression during use, it is important for medical personnel to be able to advance the catheter through a vessel, sometimes against significant frictional resistance, without undue axial compression or snaking of the catheter shaft. Shaft compression can result in a loss of control for the medical practitioner and can complicate the positioning of the distal end of the catheter shaft at a desired location for a medical procedure. In addition, medical personnel may rely on tactile feedback to attain and verify proper positioning of the catheter, and such feedback can be impaired by excessive compressibility.
The foregoing discussion is intended only to illustrate the present field and should not be taken as a disavowal of claim scope.